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<FONT color="green">001</FONT>    /*<a name="line.1"></a>
<FONT color="green">002</FONT>     * Licensed to the Apache Software Foundation (ASF) under one or more<a name="line.2"></a>
<FONT color="green">003</FONT>     * contributor license agreements.  See the NOTICE file distributed with<a name="line.3"></a>
<FONT color="green">004</FONT>     * this work for additional information regarding copyright ownership.<a name="line.4"></a>
<FONT color="green">005</FONT>     * The ASF licenses this file to You under the Apache License, Version 2.0<a name="line.5"></a>
<FONT color="green">006</FONT>     * (the "License"); you may not use this file except in compliance with<a name="line.6"></a>
<FONT color="green">007</FONT>     * the License.  You may obtain a copy of the License at<a name="line.7"></a>
<FONT color="green">008</FONT>     *<a name="line.8"></a>
<FONT color="green">009</FONT>     *      http://www.apache.org/licenses/LICENSE-2.0<a name="line.9"></a>
<FONT color="green">010</FONT>     *<a name="line.10"></a>
<FONT color="green">011</FONT>     * Unless required by applicable law or agreed to in writing, software<a name="line.11"></a>
<FONT color="green">012</FONT>     * distributed under the License is distributed on an "AS IS" BASIS,<a name="line.12"></a>
<FONT color="green">013</FONT>     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.<a name="line.13"></a>
<FONT color="green">014</FONT>     * See the License for the specific language governing permissions and<a name="line.14"></a>
<FONT color="green">015</FONT>     * limitations under the License.<a name="line.15"></a>
<FONT color="green">016</FONT>     */<a name="line.16"></a>
<FONT color="green">017</FONT>    package org.apache.commons.math3.transform;<a name="line.17"></a>
<FONT color="green">018</FONT>    <a name="line.18"></a>
<FONT color="green">019</FONT>    import java.util.Arrays;<a name="line.19"></a>
<FONT color="green">020</FONT>    <a name="line.20"></a>
<FONT color="green">021</FONT>    import org.apache.commons.math3.complex.Complex;<a name="line.21"></a>
<FONT color="green">022</FONT>    import org.apache.commons.math3.exception.DimensionMismatchException;<a name="line.22"></a>
<FONT color="green">023</FONT>    import org.apache.commons.math3.exception.MathIllegalArgumentException;<a name="line.23"></a>
<FONT color="green">024</FONT>    import org.apache.commons.math3.exception.util.LocalizedFormats;<a name="line.24"></a>
<FONT color="green">025</FONT>    <a name="line.25"></a>
<FONT color="green">026</FONT>    /**<a name="line.26"></a>
<FONT color="green">027</FONT>     * Useful functions for the implementation of various transforms.<a name="line.27"></a>
<FONT color="green">028</FONT>     *<a name="line.28"></a>
<FONT color="green">029</FONT>     * @version $Id: TransformUtils.java 1385310 2012-09-16 16:32:10Z tn $<a name="line.29"></a>
<FONT color="green">030</FONT>     * @since 3.0<a name="line.30"></a>
<FONT color="green">031</FONT>     */<a name="line.31"></a>
<FONT color="green">032</FONT>    public class TransformUtils {<a name="line.32"></a>
<FONT color="green">033</FONT>        /**<a name="line.33"></a>
<FONT color="green">034</FONT>         * Table of the powers of 2 to facilitate binary search lookup.<a name="line.34"></a>
<FONT color="green">035</FONT>         *<a name="line.35"></a>
<FONT color="green">036</FONT>         * @see #exactLog2(int)<a name="line.36"></a>
<FONT color="green">037</FONT>         */<a name="line.37"></a>
<FONT color="green">038</FONT>        private static final int[] POWERS_OF_TWO = {<a name="line.38"></a>
<FONT color="green">039</FONT>            0x00000001, 0x00000002, 0x00000004, 0x00000008, 0x00000010, 0x00000020,<a name="line.39"></a>
<FONT color="green">040</FONT>            0x00000040, 0x00000080, 0x00000100, 0x00000200, 0x00000400, 0x00000800,<a name="line.40"></a>
<FONT color="green">041</FONT>            0x00001000, 0x00002000, 0x00004000, 0x00008000, 0x00010000, 0x00020000,<a name="line.41"></a>
<FONT color="green">042</FONT>            0x00040000, 0x00080000, 0x00100000, 0x00200000, 0x00400000, 0x00800000,<a name="line.42"></a>
<FONT color="green">043</FONT>            0x01000000, 0x02000000, 0x04000000, 0x08000000, 0x10000000, 0x20000000,<a name="line.43"></a>
<FONT color="green">044</FONT>            0x40000000<a name="line.44"></a>
<FONT color="green">045</FONT>        };<a name="line.45"></a>
<FONT color="green">046</FONT>    <a name="line.46"></a>
<FONT color="green">047</FONT>        /** Private constructor. */<a name="line.47"></a>
<FONT color="green">048</FONT>        private TransformUtils() {<a name="line.48"></a>
<FONT color="green">049</FONT>            super();<a name="line.49"></a>
<FONT color="green">050</FONT>        }<a name="line.50"></a>
<FONT color="green">051</FONT>    <a name="line.51"></a>
<FONT color="green">052</FONT>        /**<a name="line.52"></a>
<FONT color="green">053</FONT>         * Multiply every component in the given real array by the<a name="line.53"></a>
<FONT color="green">054</FONT>         * given real number. The change is made in place.<a name="line.54"></a>
<FONT color="green">055</FONT>         *<a name="line.55"></a>
<FONT color="green">056</FONT>         * @param f the real array to be scaled<a name="line.56"></a>
<FONT color="green">057</FONT>         * @param d the real scaling coefficient<a name="line.57"></a>
<FONT color="green">058</FONT>         * @return a reference to the scaled array<a name="line.58"></a>
<FONT color="green">059</FONT>         */<a name="line.59"></a>
<FONT color="green">060</FONT>        public static double[] scaleArray(double[] f, double d) {<a name="line.60"></a>
<FONT color="green">061</FONT>    <a name="line.61"></a>
<FONT color="green">062</FONT>            for (int i = 0; i &lt; f.length; i++) {<a name="line.62"></a>
<FONT color="green">063</FONT>                f[i] *= d;<a name="line.63"></a>
<FONT color="green">064</FONT>            }<a name="line.64"></a>
<FONT color="green">065</FONT>            return f;<a name="line.65"></a>
<FONT color="green">066</FONT>        }<a name="line.66"></a>
<FONT color="green">067</FONT>    <a name="line.67"></a>
<FONT color="green">068</FONT>        /**<a name="line.68"></a>
<FONT color="green">069</FONT>         * Multiply every component in the given complex array by the<a name="line.69"></a>
<FONT color="green">070</FONT>         * given real number. The change is made in place.<a name="line.70"></a>
<FONT color="green">071</FONT>         *<a name="line.71"></a>
<FONT color="green">072</FONT>         * @param f the complex array to be scaled<a name="line.72"></a>
<FONT color="green">073</FONT>         * @param d the real scaling coefficient<a name="line.73"></a>
<FONT color="green">074</FONT>         * @return a reference to the scaled array<a name="line.74"></a>
<FONT color="green">075</FONT>         */<a name="line.75"></a>
<FONT color="green">076</FONT>        public static Complex[] scaleArray(Complex[] f, double d) {<a name="line.76"></a>
<FONT color="green">077</FONT>    <a name="line.77"></a>
<FONT color="green">078</FONT>            for (int i = 0; i &lt; f.length; i++) {<a name="line.78"></a>
<FONT color="green">079</FONT>                f[i] = new Complex(d * f[i].getReal(), d * f[i].getImaginary());<a name="line.79"></a>
<FONT color="green">080</FONT>            }<a name="line.80"></a>
<FONT color="green">081</FONT>            return f;<a name="line.81"></a>
<FONT color="green">082</FONT>        }<a name="line.82"></a>
<FONT color="green">083</FONT>    <a name="line.83"></a>
<FONT color="green">084</FONT>    <a name="line.84"></a>
<FONT color="green">085</FONT>        /**<a name="line.85"></a>
<FONT color="green">086</FONT>         * Builds a new two dimensional array of {@code double} filled with the real<a name="line.86"></a>
<FONT color="green">087</FONT>         * and imaginary parts of the specified {@link Complex} numbers. In the<a name="line.87"></a>
<FONT color="green">088</FONT>         * returned array {@code dataRI}, the data is laid out as follows<a name="line.88"></a>
<FONT color="green">089</FONT>         * &lt;ul&gt;<a name="line.89"></a>
<FONT color="green">090</FONT>         * &lt;li&gt;{@code dataRI[0][i] = dataC[i].getReal()},&lt;/li&gt;<a name="line.90"></a>
<FONT color="green">091</FONT>         * &lt;li&gt;{@code dataRI[1][i] = dataC[i].getImaginary()}.&lt;/li&gt;<a name="line.91"></a>
<FONT color="green">092</FONT>         * &lt;/ul&gt;<a name="line.92"></a>
<FONT color="green">093</FONT>         *<a name="line.93"></a>
<FONT color="green">094</FONT>         * @param dataC the array of {@link Complex} data to be transformed<a name="line.94"></a>
<FONT color="green">095</FONT>         * @return a two dimensional array filled with the real and imaginary parts<a name="line.95"></a>
<FONT color="green">096</FONT>         *   of the specified complex input<a name="line.96"></a>
<FONT color="green">097</FONT>         */<a name="line.97"></a>
<FONT color="green">098</FONT>        public static double[][] createRealImaginaryArray(final Complex[] dataC) {<a name="line.98"></a>
<FONT color="green">099</FONT>            final double[][] dataRI = new double[2][dataC.length];<a name="line.99"></a>
<FONT color="green">100</FONT>            final double[] dataR = dataRI[0];<a name="line.100"></a>
<FONT color="green">101</FONT>            final double[] dataI = dataRI[1];<a name="line.101"></a>
<FONT color="green">102</FONT>            for (int i = 0; i &lt; dataC.length; i++) {<a name="line.102"></a>
<FONT color="green">103</FONT>                final Complex c = dataC[i];<a name="line.103"></a>
<FONT color="green">104</FONT>                dataR[i] = c.getReal();<a name="line.104"></a>
<FONT color="green">105</FONT>                dataI[i] = c.getImaginary();<a name="line.105"></a>
<FONT color="green">106</FONT>            }<a name="line.106"></a>
<FONT color="green">107</FONT>            return dataRI;<a name="line.107"></a>
<FONT color="green">108</FONT>        }<a name="line.108"></a>
<FONT color="green">109</FONT>    <a name="line.109"></a>
<FONT color="green">110</FONT>        /**<a name="line.110"></a>
<FONT color="green">111</FONT>         * Builds a new array of {@link Complex} from the specified two dimensional<a name="line.111"></a>
<FONT color="green">112</FONT>         * array of real and imaginary parts. In the returned array {@code dataC},<a name="line.112"></a>
<FONT color="green">113</FONT>         * the data is laid out as follows<a name="line.113"></a>
<FONT color="green">114</FONT>         * &lt;ul&gt;<a name="line.114"></a>
<FONT color="green">115</FONT>         * &lt;li&gt;{@code dataC[i].getReal() = dataRI[0][i]},&lt;/li&gt;<a name="line.115"></a>
<FONT color="green">116</FONT>         * &lt;li&gt;{@code dataC[i].getImaginary() = dataRI[1][i]}.&lt;/li&gt;<a name="line.116"></a>
<FONT color="green">117</FONT>         * &lt;/ul&gt;<a name="line.117"></a>
<FONT color="green">118</FONT>         *<a name="line.118"></a>
<FONT color="green">119</FONT>         * @param dataRI the array of real and imaginary parts to be transformed<a name="line.119"></a>
<FONT color="green">120</FONT>         * @return an array of {@link Complex} with specified real and imaginary parts.<a name="line.120"></a>
<FONT color="green">121</FONT>         * @throws DimensionMismatchException if the number of rows of the specified<a name="line.121"></a>
<FONT color="green">122</FONT>         *   array is not two, or the array is not rectangular<a name="line.122"></a>
<FONT color="green">123</FONT>         */<a name="line.123"></a>
<FONT color="green">124</FONT>        public static Complex[] createComplexArray(final double[][] dataRI)<a name="line.124"></a>
<FONT color="green">125</FONT>            throws DimensionMismatchException{<a name="line.125"></a>
<FONT color="green">126</FONT>    <a name="line.126"></a>
<FONT color="green">127</FONT>            if (dataRI.length != 2) {<a name="line.127"></a>
<FONT color="green">128</FONT>                throw new DimensionMismatchException(dataRI.length, 2);<a name="line.128"></a>
<FONT color="green">129</FONT>            }<a name="line.129"></a>
<FONT color="green">130</FONT>            final double[] dataR = dataRI[0];<a name="line.130"></a>
<FONT color="green">131</FONT>            final double[] dataI = dataRI[1];<a name="line.131"></a>
<FONT color="green">132</FONT>            if (dataR.length != dataI.length) {<a name="line.132"></a>
<FONT color="green">133</FONT>                throw new DimensionMismatchException(dataI.length, dataR.length);<a name="line.133"></a>
<FONT color="green">134</FONT>            }<a name="line.134"></a>
<FONT color="green">135</FONT>    <a name="line.135"></a>
<FONT color="green">136</FONT>            final int n = dataR.length;<a name="line.136"></a>
<FONT color="green">137</FONT>            final Complex[] c = new Complex[n];<a name="line.137"></a>
<FONT color="green">138</FONT>            for (int i = 0; i &lt; n; i++) {<a name="line.138"></a>
<FONT color="green">139</FONT>                c[i] = new Complex(dataR[i], dataI[i]);<a name="line.139"></a>
<FONT color="green">140</FONT>            }<a name="line.140"></a>
<FONT color="green">141</FONT>            return c;<a name="line.141"></a>
<FONT color="green">142</FONT>        }<a name="line.142"></a>
<FONT color="green">143</FONT>    <a name="line.143"></a>
<FONT color="green">144</FONT>    <a name="line.144"></a>
<FONT color="green">145</FONT>        /**<a name="line.145"></a>
<FONT color="green">146</FONT>         * Returns the base-2 logarithm of the specified {@code int}. Throws an<a name="line.146"></a>
<FONT color="green">147</FONT>         * exception if {@code n} is not a power of two.<a name="line.147"></a>
<FONT color="green">148</FONT>         *<a name="line.148"></a>
<FONT color="green">149</FONT>         * @param n the {@code int} whose base-2 logarithm is to be evaluated<a name="line.149"></a>
<FONT color="green">150</FONT>         * @return the base-2 logarithm of {@code n}<a name="line.150"></a>
<FONT color="green">151</FONT>         * @throws MathIllegalArgumentException if {@code n} is not a power of two<a name="line.151"></a>
<FONT color="green">152</FONT>         */<a name="line.152"></a>
<FONT color="green">153</FONT>        public static int exactLog2(final int n)<a name="line.153"></a>
<FONT color="green">154</FONT>            throws MathIllegalArgumentException {<a name="line.154"></a>
<FONT color="green">155</FONT>    <a name="line.155"></a>
<FONT color="green">156</FONT>            int index = Arrays.binarySearch(TransformUtils.POWERS_OF_TWO, n);<a name="line.156"></a>
<FONT color="green">157</FONT>            if (index &lt; 0) {<a name="line.157"></a>
<FONT color="green">158</FONT>                throw new MathIllegalArgumentException(<a name="line.158"></a>
<FONT color="green">159</FONT>                        LocalizedFormats.NOT_POWER_OF_TWO_CONSIDER_PADDING,<a name="line.159"></a>
<FONT color="green">160</FONT>                        Integer.valueOf(n));<a name="line.160"></a>
<FONT color="green">161</FONT>            }<a name="line.161"></a>
<FONT color="green">162</FONT>            return index;<a name="line.162"></a>
<FONT color="green">163</FONT>        }<a name="line.163"></a>
<FONT color="green">164</FONT>    }<a name="line.164"></a>




























































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